A steam turbine installed in a power generation facility such as a nuclear power plant and a thermal power plant requires lubricant to be continuously and stably supplied to turbine bearings thereof for the purpose of steam turbine protection. In light of this, a lubricant system is installed in a power generation facility.
A conventional lubricant system has two motor-driven pumps as main oil pumps, one for a service pump and one for a standby pump. In addition, the lubricant system has a DC motor-driven emergency pump for emergency use (for example, see Patent Literature 1).
There has been known a cold and hot water pump apparatus for use in an air conditioning facility including a plurality of cold and hot water pumps operating in parallel and a two-way valve controlling to a constant pressure on a discharge side of each cold and hot water pump.